Relay node authentication method and system

The invention discloses a relay node authentication method. The method comprises the following steps: key negotiation authentication is carried out between a mobility management entity (MME) and a relay node (RN), and related messages for carrying out the key negotiation authentication are carried out by non-access stratum messages; authentication between the MME and a relay node platform of the RN is completed through the key negotiation authentication, and symmetric equipment keys are established; and the MME and the RN respectively bindings the symmetric equipment keys and an evolved packet system (EPS) to generate a new EPS safe key. The invention also discloses a relay node authentication system, a key negotiation authentication unit in the system is used for achieving key negotiation authentication between the MME and the RN, and related messages for carrying out the key negotiation authentication are carried out by non-access stratum messages. By adopting the method and the system which are provided by the invention, the security of communication data between the relay node and the network is ensured while the relay node authentication is completed.